Promotion of ordinary growth and development of crops for their increased production has been a big task in the agricultural technology. This task is becoming more important because food shortage on global scale is anticipated in the future.
The method for achieving the task includes a method by a technique employing an agricultural facility capable of controlling the temperature, light, etc. applied. This method, however, has had problems in that the facility and equipment therefor are required and that the method has a limitation as compared to the labor needed for said control.
Meanwhile, there have recently been made attempts of isolating a physiologically active substance from plant tissue samples and studying its effect on the life cycle (germination, growth, blooming, bearing and aging) of plants in order to promote their growth and development for increased production. However, the number of cases is very small yet in which a physiologically active substance having a plus effect on the growth and development of plants has been put into practical use. Moreover, the number of substances is also very small which can exhibit a growth promotion action on plants in their actual outdoor cultivation.
Under the above situation, the present inventors made an extensive study and, as a result, found out that certain jasmonic acid derivatives have a growth promotion action on plants. The finding has led to the completion of the present invention.